JP2017087533A - Liquid spray head and liquid spray device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid spray head in which nozzle holes 6 of a nozzle plate 5 can be surely aligned to channels 3 of an actuator substrate 2.SOLUTION: A liquid spray head 1 comprises: an actuator substrate 2 in which a plurality of channels 3 having opening parts 3aa on a surface (a lower surface LS) at a liquid droplet discharge side are arrayed in a reference direction K to constitute a channel row 4; and a nozzle plate 5 which has nozzle holes 6 communicated with the channels 3 and is arranged on the surface (the lower surface LS) at the liquid droplet discharge side of the actuator substrate 2. The nozzle plate 5 comprises protrusions 7 to be fitted to the opening parts 3aa.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a liquid ejecting head and a liquid ejecting apparatus that eject and record liquid droplets on a recording medium.

  In recent years, an ink jet type liquid ejecting head has been used in which ink droplets are ejected onto recording paper or the like to record characters and figures, or a liquid material is ejected onto the surface of an element substrate to form a functional thin film. In this method, a liquid such as ink or liquid material is guided from a liquid tank to a channel via a supply pipe, pressure is applied to the liquid filled in the channel, and the liquid is discharged as a droplet from a nozzle communicating with the channel. When ejecting droplets, the liquid ejecting head and the recording medium are moved to record characters and figures, or a functional thin film having a predetermined shape is formed.

  For example, Patent Document 1 describes a liquid ejecting head that applies a pressure to ink filled in a pressure generation chamber by a piezoelectric vibrator and ejects ink droplets from a nozzle opening communicating with the pressure generation chamber. The liquid ejecting head includes a structure in which a base, an elastic plate, a flow path forming substrate, and a nozzle plate are stacked. A plurality of piezoelectric vibrators arranged in a straight line are installed on the base. The elastic plate is laminated on the piezoelectric vibrator, and transmits the vibration of the piezoelectric vibrator to the pressure generating chamber of the flow path forming substrate laminated on the elastic plate. The flow path forming substrate includes a common ink chamber and a plurality of pressure generation chambers communicating with the common ink chamber, and the plurality of pressure generation chambers are respectively installed corresponding to the plurality of piezoelectric vibrators. The nozzle plate includes a plurality of nozzle openings, and the plurality of nozzle openings communicate with the plurality of pressure generation chambers, respectively.

  The nozzle plate includes a vertical wall extending toward the base on the outer periphery of the flat portion where the nozzle openings are arranged. It is described that the vertical wall of the nozzle plate is fitted into a base and a flow path forming substrate stacked on the top of the base to align each pressure generating chamber and each nozzle opening. A convex portion that protrudes toward the nozzle plate is installed in advance on the outer edge portion of the flow path forming substrate, and a convex portion that protrudes toward the ink droplet ejection side is formed on the nozzle plate. Is described in that the convex portion of the nozzle plate is fitted into the nozzle plate to perform alignment between the pressure generating chamber and the nozzle opening.

JP 2001-347659 A

  In recent years, the number of nozzle openings formed in the nozzle plate has increased, and the arrangement pitch of nozzle openings has become extremely narrow. For this reason, it is extremely difficult to align the pressure generating chamber and the nozzle opening only at both ends of the nozzle row in which the nozzle openings are arranged. In particular, when the nozzle plate is bonded to the flow path forming substrate, a thermosetting adhesive is used. Since the nozzle plate is thermally expanded by heating, it is extremely difficult to align a large number of nozzle openings simultaneously with predetermined positions of a large number of pressure generating chambers.

  The liquid jet head of the present invention includes an actuator substrate that forms a channel row by arranging a plurality of channels having openings on the surface on the droplet discharge side in the reference direction K, and a nozzle hole that communicates with the channel. A nozzle plate installed on the surface of the actuator substrate on the droplet discharge side, and the nozzle plate has a protrusion that fits into the opening.

  Further, the protrusion has a first protrusion located in the vicinity of both ends in the reference direction of the opening.

  Further, the nozzle hole is located between the two first protrusions located substantially in the center of the opening in the reference direction.

  In addition, the channel includes a discharge channel that discharges liquid and a non-discharge channel that does not discharge liquid, and the first protrusion is fitted into the opening of the discharge channel.

  In addition, the height of the protrusion from the surface of the nozzle plate is in the range of 10 μm to 25 μm.

  Further, the protrusion has a width substantially equal to the width of the opening in the reference direction.

  In addition, the channel includes a discharge channel that discharges liquid and a non-discharge channel that does not discharge liquid, and the second protrusion is fitted into the opening of the non-discharge channel.

  Further, the protrusion is located near both ends in the orthogonal direction orthogonal to the reference direction of the opening.

  In addition, the nozzle hole is positioned approximately at the center of the width of the opening in the orthogonal direction.

  The nozzle plate has a laminated structure in which a first sheet having a flat surface and a second sheet having the protrusions on the surface are laminated.

  The liquid ejecting apparatus according to the aspect of the invention includes the liquid ejecting head, a moving mechanism that relatively moves the liquid ejecting head and the recording medium, a liquid supply pipe that supplies liquid to the liquid ejecting head, and the liquid And a liquid tank for supplying the liquid to the supply pipe.

  The liquid ejecting head according to the present invention includes an actuator substrate in which a plurality of channels having openings on the surface on the droplet discharge side are arranged in the reference direction K to form a channel row, and a nozzle hole communicating with the channel. A nozzle plate installed on the discharge side surface, and the nozzle plate includes a protrusion that fits into the opening. Thereby, the nozzle hole of the nozzle plate can be reliably aligned with the channel of the actuator substrate.

FIG. 3 is a schematic cross-sectional view of the liquid jet head according to the first embodiment of the present invention. FIG. 6 is a schematic exploded perspective view of a liquid jet head according to a second embodiment of the present invention. FIG. 10 is an explanatory diagram of a liquid jet head according to a second embodiment of the present invention. FIG. 10 is a partial cross-sectional schematic diagram in a reference direction of a liquid jet head according to a third embodiment of the present invention. FIG. 9 is a partial cross-sectional schematic diagram in a reference direction of a liquid jet head according to a fourth embodiment of the present invention. FIG. 10 is a schematic perspective view of a liquid ejecting apparatus according to a fifth embodiment of the invention.

(First embodiment)
FIG. 1 is a schematic cross-sectional view of a liquid jet head 1 according to the first embodiment of the present invention. 1A is a schematic partial sectional view in the reference direction K in which a plurality of channels 3 are arranged, and FIG. 1B is a schematic sectional view in the orthogonal direction J perpendicular to the reference direction K of the channels 3.

  As shown in FIG. 1, the liquid ejecting head 1 includes an actuator substrate 2 and a nozzle plate 5 installed on a droplet discharge side surface (hereinafter referred to as a lower surface LS) that discharges droplets of the actuator substrate 2. In the actuator substrate 2, a plurality of channels 3 having openings 3 aa on the lower surface LS are arranged in the reference direction K to form a channel row 4. The nozzle plate 5 has a nozzle hole 6 communicating with the channel 3. The nozzle plate 5 includes a protrusion 7 that fits into the opening 3aa. With this configuration, even when a large number of channels 3 are arranged at a narrow pitch in the reference direction K, the projections 7 of the nozzle plate 5 are fitted into the openings 3aa of the channels 3 of the actuator substrate 2 so that the nozzle holes 6 of the nozzle plate 5 are fitted. Can be accurately aligned with the channel 3 of the actuator substrate 2.

  This will be specifically described. The actuator substrate 2 can be a piezoelectric substrate that is polarized in the normal direction of the lower surface LS. As the piezoelectric substrate, for example, PZT (lead zirconate titanate) ceramics can be used. The actuator substrate 2 includes a plurality of channels 3 that open to the lower surface LS. A plurality of channels 3 are arranged in the reference direction K to form a channel row 4. Each channel 3 has an opening 3aa on the lower surface LS of the actuator substrate 2. In the opening 3aa, the width in the reference direction K is w1, and the width in the orthogonal direction J orthogonal to the reference direction K is w2. Two adjacent channels 3 are separated by a side wall 2w. The two side walls 2w sandwiching the channel 3 are deformed by the piezo effect to change the volume of the channel 3, and the liquid filling the channel 3 is discharged from the nozzle hole 6 as droplets. The channel width of the channel 3 in the reference direction K is the same as the width w1 of the opening 3aa in the reference direction K, and is, for example, several tens of μm to 100 μm. The width wt of the side wall 2w in the reference direction K is, for example, several tens of μm to 100 μm. The channel width of the channel 3 in the orthogonal direction J is approximately the same as the width w2 of the opening 3aa in the orthogonal direction J, and is, for example, 100 μm to several mm. The channel row 4 has 200 or more channels 3 in the reference direction K.

  The nozzle plate 5 includes a projection 7 on the surface NS on the actuator substrate 2 side. The protrusion 7 has a first protrusion 7a located in the vicinity of both ends in the reference direction K of the opening 3aa. The first ridge 7a is separated into a first ridge 7aa near one end in the reference direction K of the opening 3aa and a first ridge 7ab near the other end. That is, the space between the adjacent openings 3aa is composed of the lower end surface (lower surface LS) of the side wall 2w, and the two first protrusions 7aa and 7ab sandwich the lower end surface of the side wall 2w. The nozzle hole 6 is located between the first ridge 7aa corresponding to one side wall 2w and the first ridge 7ab corresponding to the side wall 2w adjacent to the one side wall. Moreover, the nozzle hole 6 is located in the approximate center in the reference direction K of the opening 3aa. The nozzle plate 5 can use a polyimide film or a metal thin film. The first protrusions 7aa and 7ab can be formed by an etching method or a molding method.

  As shown in FIG. 1A, the plurality of first protrusions 7 a of the nozzle plate 5 correspond to the plurality of channels 3 of the actuator substrate 2, and two adjacent first protrusions 7 aa and 7 ab are one channel 3. Is fitted into the opening 3aa. That is, the position of the nozzle hole 6 with respect to one side surface of the channel 3 is defined by one first protrusion 7aa corresponding to one side wall 2w, and the other first protrusion corresponding to the side wall 2w adjacent to the one side wall. The position of the nozzle hole 6 with respect to the other side surface of the channel 3 is defined by the stripe 7ab. As a result, the variation in the position of the nozzle hole 6 with respect to the channel 3 in the reference direction K of the channel 3 is reduced.

  The height h of the first protrusion 7a (first protrusions 7aa, 7ab) is preferably from the surface NS of the actuator substrate 2 on which the surface of the nozzle plate 5, that is, the lower end surface (lower surface LS) of the side wall 2w abuts. The range is 10 μm to 25 μm. When the height h is lower than 10 μm, the first protrusion 7a is difficult to be locked to the opening 3aa, and when the height h exceeds 25 μm, the first protrusion 7a itself changes the volume of the channel 3. .

  The width t1 of the first protrusion 7a (first protrusions 7aa, 7ab) in the reference direction K is in the range of 5 μm to (w1−r) / 2, where r is the diameter of the nozzle hole 6 on the surface NS. . When the width t1 is smaller than 5 μm, the first protrusion 7a is difficult to be locked to the opening of the channel 3, and when the width t1 exceeds (wl−r) / 2, the first protrusion 7a is formed in the nozzle hole 6. The nozzle hole 6 may be deformed and cover the discharge conditions.

  As shown in FIG. 1B, the first protrusion 7a (protrusion 7) has a width t2 in the orthogonal direction J orthogonal to the reference direction K, which is approximately the same as the width w2 of the opening 3aa in the orthogonal direction J. . That is, the 1st protrusion 7a is located in the both ends vicinity in the orthogonal direction J of opening 3aa. Further, the width t2 in the orthogonal direction J of the first protrusion 7a does not exceed the width w2 in the orthogonal direction J of the opening 3aa. The nozzle hole 6 is located at the approximate center of the width t2 in the orthogonal direction J of the first protrusion 7a. Further, in the orthogonal direction J, the position of one end of the first protrusion 7a is defined by one end of the opening 3aa that opens to the lower surface LS of the channel 3, and the position of the other end is defined by the other end of the opening 3aa of the channel 3. Is done. Therefore, in the orthogonal direction J of the channel 3, the position of the nozzle hole 6 with respect to the channel 3 is accurately positioned by the first protrusion 7a. As a result, the variation in the position of the nozzle hole 6 with respect to the channel 3 in the orthogonal direction J of the channel 3 is reduced.

  The nozzle plate 5 is bonded to the lower surface LS of the actuator substrate 2 with a thermosetting adhesive. When the nozzle plate 5 is bonded to the lower surface LS of the actuator substrate 2, heating is performed, but the first protrusion 7a is fitted into the opening 3aa of the channel 3 to prevent displacement due to thermal expansion, and all nozzle holes 6 can be accurately fixed at a predetermined position of all the channels 3. Therefore, it is possible to reduce variations in the ejection direction or ejection speed of the droplets ejected from the nozzle holes 6.

  Instead of forming the first protrusion 7a over the width w2 in the orthogonal direction J of the opening 3aa, the first protrusion 7a is not formed in the vicinity of the nozzle hole 6, and the opening 3aa You may install only in the both ends side of the orthogonal direction J. As a result, the channel width in the short direction of the channel 3 (in this embodiment, the same as the width w1 of the opening 3aa in the reference direction K) approaches the diameter r of the nozzle hole 6 opening in the surface NS of the nozzle plate 5. There is no need to change the shape of the nozzle hole 6 or the inclination angle of the side surface of the nozzle hole 6.

  Further, in the present embodiment, the protrusions 7 are formed on the nozzle plate 5 so as to correspond to all the channels 3, but the present invention is not limited to this, and one projection is provided for each of the plurality of openings 3aa arranged in the reference direction K. The structure which the two protrusions 7 may fit may be sufficient. In this embodiment, the width w1 in the reference direction K of the opening 3aa is narrower than the width w2 in the orthogonal direction J. However, the present invention is not limited to this relationship, and is orthogonal to the width w1 in the reference direction K of the opening 3aa. The width w2 in the direction J may be equal, or the width w1 in the reference direction K may be wider than the width w2 in the orthogonal direction J. In the present embodiment, all the channels 3 are ejection channels that eject droplets, but instead of this, a configuration in which ejection channels and non-ejection channels are alternately arranged in the reference direction K may be employed. Further, instead of a method of generating a pressure wave in the liquid of the channel 3 using the piezo effect of the side wall 2w and discharging a droplet from the nozzle hole 6, an actuator made of a piezoelectric material is installed on the upper portion of the actuator substrate 2. Alternatively, a method may be used in which vibration is transmitted from the actuator to the channel 3 to generate a pressure wave in the liquid in the channel 3.

(Second embodiment)
FIG. 2 is a schematic exploded perspective view of the liquid jet head 1 according to the second embodiment of the present invention. FIG. 3 is an explanatory diagram of the liquid jet head 1 according to the second embodiment of the present invention. 3A is a partial cross-sectional schematic view in the reference direction K, which is the direction of the channel row 4, FIG. 3B is a schematic cross-sectional view of the discharge channel 3a, and FIG. 3C is a non-discharge channel 3b. FIG. The same portions or portions having the same function are denoted by the same reference numerals.

  As shown in FIG. 2, the liquid ejecting head 1 includes a piezoelectric substrate 2a, a cover plate 2b installed on the upper surface US of the piezoelectric substrate 2a, and a nozzle plate 5 installed on the lower surface LS of the piezoelectric substrate 2a. Is provided. The piezoelectric substrate 2a and the cover plate 2b constitute the actuator substrate 2. In the actuator substrate 2, a plurality of channels 3 having openings on the lower surface LS on the droplet discharge side are arranged in the reference direction K to form a channel row 4. The channel 3 includes a discharge channel 3a that discharges liquid and a non-discharge channel 3b that does not discharge liquid. The discharge channel 3a has an opening 3aa on the lower surface LS, and the non-discharge channel 3b has an opening 3ba on the lower surface LS. The nozzle plate 5 has a nozzle hole 6 communicating with the discharge channel 3 a and is installed on the lower surface LS on the droplet discharge side of the actuator substrate 2. The nozzle plate 5 includes a first protrusion 7a (protrusion 7) that fits into the opening 3aa on the surface NS on the actuator substrate 2 side. The first ridge 7a has two first ridges 7aa and 7ab protruding along two side surfaces of the discharge channel 3a, and the two first ridges 7aa and 7ab are fitted into the opening 3aa. .

  This will be specifically described. The ejection channels 3a and the non-ejection channels 3b penetrate the piezoelectric substrate 2a in the plate thickness direction, and are alternately arranged in the reference direction K to constitute the channel row 4. The cover plate 2b includes two liquid chambers 2ba and 2bb which are separated from each other. The two liquid chambers 2ba and 2bb communicate with both ends of the plurality of discharge channels 3a in the orthogonal direction J orthogonal to the reference direction K, respectively. The discharge channel 3a and the non-discharge channel 3b are formed by grinding with a disk-shaped blade having diamond abrasive grains embedded in the outer periphery. Therefore, the arc shape of the blade remains at both ends in the orthogonal direction J. The discharge channel 3a is formed by grinding from the upper surface US side of the piezoelectric substrate 2a, and both end portions of the discharge channel 3a are inclined surfaces that rise from the lower surface LS to the upper surface US. The non-discharge channel 3b reaches the cover plate 2b from the lower surface LS side of the piezoelectric substrate 2a and is formed by grinding to a depth that does not reach the liquid chambers 2ba and 2bb. It forms an inclined surface that cuts down to the LS side. The non-ejection channel 3b extends to one side surface SS of the piezoelectric substrate 2a. The non-ejection channel 3b in the extending region has a depth from the lower surface LS deeper than ½ of the thickness of the piezoelectric substrate 2a, but does not reach the upper surface US. The opening 3ab of the discharge channel 3a that opens to the upper surface US of the piezoelectric substrate 2a is wider in the orthogonal direction J than the opening 3bb of the non-discharge channel 3b that opens to the upper surface US.

  As shown in FIGS. 3A and 3B, the piezoelectric substrate 2a has openings 3aa and openings 3ba that alternately open in the reference direction K of the lower surface LS. The opening 3aa is an opening of the discharge channel 3a, and the opening 3ba is an opening of the non-discharge channel 3b. The opening 3aa of the discharge channel 3a has a narrower width in the orthogonal direction J than the opening 3ba of the non-discharge channel 3b, and the opening 3ba of the non-discharge channel 3b extends from the front of one end of the lower surface LS to the other end. Extends to side SS.

  The nozzle plate 5 includes a plurality of first protrusions 7a (protrusions 7) on the surface NS on the actuator substrate 2 side. The first ridge 7a has a first ridge 7aa and a first ridge 7ab located near both ends in the reference direction K of the opening 3aa. The nozzle hole 6 is located between the first ridge 7aa corresponding to one side wall 2w and the first ridge 7ab corresponding to the side wall 2w adjacent to the one side wall. Moreover, the nozzle hole 6 is located in the approximate center in the reference direction K of the opening 3aa. Two adjacent first protrusions 7aa and 7ab are fitted into one opening 3aa. That is, the position of the nozzle hole 6 with respect to one side surface of the discharge channel 3a is defined by one first protrusion 7aa corresponding to one side wall 2w of the two adjacent first protrusions 7aa and 7ab. The position of the nozzle hole 6 relative to the other side surface of the discharge channel 3a is defined by the other first protrusion 7ab corresponding to the side wall 2w adjacent to the one side wall. As a result, the position of the nozzle hole 6 in the reference direction K of the discharge channel 3a is accurately positioned in all the discharge channels 3a. Similarly, in the orthogonal direction J of the discharge channel 3a, the position of one end of the first protrusion 7a is defined by one end of the opening 3aa of the discharge channel 3a, and the position of the other end of the first protrusion 7a is the position of the discharge channel 3a. It is defined by the other end of the opening 3aa. That is, in the orthogonal direction J of the discharge channel 3a, the position of the nozzle hole 6 with respect to the discharge channel 3a can be accurately positioned by the first protrusion 7a. As a result, variation in the position of the nozzle hole 6 with respect to the discharge channel 3a is reduced.

  As shown in FIG. 3B, the ejection channel 3a includes a common electrode 8a on the side surface below the half of the thickness of the piezoelectric substrate 2a. As shown in FIG. 3C, the non-ejection channel 3b includes an individual electrode 8b on a side surface lower than about ½ of the thickness of the piezoelectric substrate 2a. The piezoelectric substrate 2a includes, on the lower surface LS, a common terminal 9a that is electrically connected to the common electrode 8a and an individual terminal 9b that is electrically connected to the individual electrode 8b. The individual terminal 9b is located between the two adjacent non-ejection channels 3b and is located on the lower surface LS near the side surface SS. The common terminal 9a is located on the lower surface LS between the end of the discharge channel 3a and the individual terminal 9b. The common terminal 9a is electrically connected to two common electrodes 8a located on both side surfaces of the discharge channel 3a. The individual terminal 9b is electrically connected to two individual electrodes 8b located on the side surface of the two non-ejection channels 3b sandwiching the ejection channel 3a on the ejection channel 3a side.

  The cover plate 2b is bonded to the upper surface US of the piezoelectric substrate 2a with an adhesive. The cover plate 2b closes the upper part of the discharge channel 3a and fixes the upper end of the side wall 2w sandwiching the discharge channel 3a. The cover plate 2b includes two liquid chambers 2ba and 2bb which are separated from each other. One liquid chamber 2ba communicates with one end of the plurality of discharge channels 3a, and the other liquid chamber 2bb communicates with the other end of the plurality of discharge channels 3a. None of the liquid chambers 2ba and 2bb communicate with the non-ejection channel 3b. Accordingly, when a liquid is supplied to one liquid chamber 2ba, the liquid flows into the plurality of discharge channels 3a, and further, the liquid flows out from the plurality of discharge channels 3a to the other liquid chamber 2bb. That is, the liquid can be circulated. Further, the liquid can be supplied to both the liquid chambers 2ba and 2bb, and the liquid can be supplied from both the liquid chambers 2ba and 2bb to the plurality of discharge channels 3a.

  The nozzle plate 5 is bonded to the lower surface LS of the piezoelectric substrate 2a with an adhesive so that a part of the individual terminal 9b and the common terminal 9a is exposed. The nozzle plate 5 is bonded to the piezoelectric substrate 2a by fitting the first protrusions 7aa and 7ab into the opening 3aa of the discharge channel 3a. At this time, the first protrusions 7aa and 7ab also function as stoppers for preventing excess adhesive from flowing into the discharge channel 3a. It is possible to prevent the adhesive from flowing into the discharge channel 3a to change the volume of the discharge channel 3a and change the discharge conditions of the liquid droplets discharged from the nozzle holes 6.

  The nozzle plate 5 is bonded to the lower surface LS of the actuator substrate 2 with a thermosetting adhesive. When the nozzle plate 5 is bonded to the lower surface LS of the actuator substrate 2, heating is performed, but the first protrusions 7aa and 7ab are fitted into the opening 3aa of the discharge channel 3a to prevent misalignment due to thermal expansion. The nozzle holes 6 can be accurately fixed at predetermined positions of all the discharge channels 3a. Therefore, it is possible to reduce variations in the ejection direction or ejection speed of the droplets ejected from the nozzle holes 6.

  PZT ceramics can be used for the piezoelectric substrate 2a. The piezoelectric substrate 2a is previously polarized in the normal direction of the lower surface LS or the upper surface US. For the cover plate 2b, PZT ceramics, other ceramics, synthetic resin, or the like can be used. If the cover plate 2b and the piezoelectric substrate 2a are made of the same material, for example, PZT ceramics, it is possible to prevent the actuator substrate 2 from being deformed due to temperature changes. The nozzle plate 5 can use a polyimide film or a metal film. The channel width of the ejection channel 3a and the non-ejection channel 3b of the piezoelectric substrate 2a and the width wt in the reference direction K of the side wall 2w separating the ejection channel 3a and the non-ejection channel 3b are, for example, several tens of μm to 100 μm. The width w2 in the orthogonal direction J of the opening 3aa where the discharge channel 3a opens to the lower surface LS is, for example, 100 μm to several mm. The height h of the first protrusions 7aa and 7ab formed on the nozzle plate 5 is preferably in the range of 10 μm to 25 μm. The width t1 of the first protrusions 7aa and 7ab in the reference direction K is preferably 5 μm to (wl−r), where r is the diameter of the nozzle hole 6 on the surface NS and wl is the channel width of the discharge channel 3a in the reference direction K. The range is / 2.

  The liquid jet head 1 further includes a flexible circuit board (not shown). The flexible circuit board has a wiring pattern and is installed on the lower surface LS of the piezoelectric substrate 2a. The wiring pattern and the common terminal 9a, and the wiring pattern and the individual terminal 9b are electrically connected. In the present embodiment, the flexible circuit board is connected to the lower surface LS on the droplet discharge side of the piezoelectric substrate 2a. Since it is not necessary to provide the flexible circuit board on the cover plate 2b side of the piezoelectric substrate 2a, the flexible circuit board can be easily mounted, and the structure on the cover plate 2b side can be simplified.

  The liquid jet head 1 is driven as follows. The liquid is supplied to the liquid chamber 2ba or the liquid chamber 2bb of the cover plate 2b, or both the liquid chambers 2ba and 2bb, and the discharge channel 3a is filled with the liquid. Next, a drive signal is given to the common terminal 9a and the individual terminal 9b through a flexible circuit board (not shown). Specifically, the common terminal 9a is connected to GND, and a drive signal is given to the individual terminal 9b. Then, the two side walls 2w sandwiching the discharge channel 3a are subjected to thickness sliding deformation, and the volume of the discharge channel 3a is instantaneously changed. For example, the volume of the discharge channel 3a expands to draw liquid from the liquid chambers 2ba and 2bb, and then the volume of the discharge channel 3a decreases to discharge droplets from the nozzle holes 6. The liquid contacts the common electrode 8a but does not contact the individual electrode 8b. Therefore, electrolysis does not occur even when a conductive liquid is used.

  In this embodiment, the piezoelectric substrate 2a is uniformly polarized in the normal direction of the lower surface LS. Instead, two piezoelectric substrates that are polarized in opposite directions are laminated. The piezoelectric substrate 2a may be used. Further, the common terminal 9a and the individual terminal 9b may be provided on the upper surface US of the piezoelectric substrate 2a. In this case, the common electrode 8a and the individual electrode 8b are installed on the side surface above 1/2 of the depth of the discharge channel 3a and the non-discharge channel 3b. In the present embodiment, the projection NS corresponding to the non-ejection channel 3b is not provided on the surface NS of the nozzle plate 5, but the projection 7 corresponding to the non-ejection channel 3b (first projection 7a) may be added. . Further, instead of forming the first protrusion 7a to have a width extending in the orthogonal direction J of the opening 3aa, the first protrusion 7a is not formed in the vicinity of the nozzle hole 6 and is orthogonal to the opening 3aa. You may install only in the both ends in the direction J.

(Third embodiment)
FIG. 4 is a partial schematic cross-sectional view in the reference direction K of the liquid jet head 1 according to the third embodiment of the present invention. The difference from the first embodiment is the shape of the projection 7 installed on the nozzle plate 5 and the opening into which the projection 7 is fitted. The same portions or portions having the same function are denoted by the same reference numerals.

  As shown in FIG. 4, the liquid ejecting head 1 includes an actuator substrate 2 and a nozzle plate 5 installed on the lower surface LS on the droplet discharge side of the actuator substrate 2. The actuator substrate 2 forms a channel row 4 by alternately arranging discharge channels 3a having openings 3aa that open to the lower surface LS and non-discharge channels 3b having openings 3ba. The nozzle plate 5 has a nozzle hole 6 communicating with the discharge channel 3a. The nozzle plate 5 includes a second protrusion 7b (protrusion 7) that fits into the opening 3ba of the non-ejection channel 3b. The second protrusion 7b has a width substantially equal to the width w3 of the opening 3ba in the reference direction K. With this configuration, even when a large number of discharge channels 3 a and non-discharge channels 3 b are arranged at a narrow pitch in the reference direction K, the second protrusion 7 b of the nozzle plate 5 is fitted into the opening 3 ba of the actuator substrate 2, and the nozzle The nozzle hole 6 of the plate 5 can be reliably aligned with the discharge channel 3 a of the actuator substrate 2.

  This will be specifically described. On the lower surface LS of the actuator substrate 2, the opening 3aa of the discharge channel 3a and the opening 3ba of the non-discharge channel 3b are alternately arranged in the reference direction K. The side wall 2w separates the discharge channel 3a and the non-discharge channel 3b. The channel width in the reference direction K of the ejection channel 3a and the non-ejection channel 3b is the same as the width w1 in the reference direction K of the opening 3aa and the width w3 in the reference direction K of the opening 3ba, for example, several tens to 100 μm. . The width wt of the side wall 2w in the reference direction K is, for example, several tens of μm to 100 μm. The channel width in the orthogonal direction J of the discharge channel 3a and the non-discharge channel 3b is approximately the same as the width in the orthogonal direction J of the opening 3aa and the width in the orthogonal direction J of the opening 3ba, for example, several hundreds μm to several mm. . The width of the second protrusion 7b in the reference direction K is substantially the same as the width w3 in the reference direction K of the opening 3ba of the non-ejection channel 3b, and the width in the orthogonal direction J is orthogonal to the opening 3ba of the non-ejection channel 3b. It is about the same as the width in direction J. Note that the second protrusions 7b may be installed only at both ends of the opening 3ba in the orthogonal direction J instead of being formed over both ends of the opening 3ba in the orthogonal direction J.

  Thereby, each nozzle hole 6 of the nozzle plate 5 can be accurately aligned with each discharge channel 3a. Although heating is performed when the nozzle plate 5 is bonded to the lower surface LS of the actuator substrate 2, the second protrusion 7b can be fitted into the opening 3ba of the non-ejection channel 3b to prevent displacement due to thermal expansion. .

  The thickness of the nozzle plate 5 is t, and the second protrusion 7b has a height h from the surface NS of the nozzle plate 5 of preferably 10 μm to t. When the height h is lower than 10 μm, the second protrusion 7b is difficult to be locked to the opening 3ba, and when the height h exceeds the thickness t of the nozzle plate 5, the second protrusion 7b is moved to the opening 3ba. Workability at the time of fitting decreases.

  In addition, the 2nd protrusion 7b can be installed in the position corresponding to the discharge channel 3a in addition to the position corresponding to the non-discharge channel 3b or instead of the position corresponding to the non-discharge channel 3b. In this case, the volume of the discharge channel 3a is smaller than the volume of the second ridge 7b and when the second ridge 7b is not installed, but this decrease in volume compensates by forming the depth of the discharge channel 3a deeply. be able to. Moreover, since the nozzle hole 6 penetrates the second protrusion 7b and the nozzle plate 5, the nozzle hole 6 has a different shape from the nozzle hole 6 when the second protrusion 7b is not installed. If the thickness is obtained by subtracting the height h of the protrusion 7b, the shape of the nozzle hole 6 can be maintained. Further, instead of forming the second ridge 7b corresponding to the discharge channel 3a across the width in the orthogonal direction J of the opening 3aa, the second ridge 7b is not formed in the vicinity of the nozzle hole 6, You may form only in the both ends side of opening part 3aa. If the second ridge 7b that fits into the opening 3aa is formed in this way, the volume change accompanying the installation of the second ridge 7b of the discharge channel 3a is small, and the shape of the nozzle hole 6 need not be changed. The second protrusion 7b of the present embodiment can be applied to the liquid jet head 1 of the second embodiment.

(Fourth embodiment)
FIG. 5 is a partial schematic cross-sectional view in the reference direction K of the liquid jet head 1 according to the fourth embodiment of the present invention. The difference from the first embodiment or the second embodiment is that the nozzle plate 5 has a laminated structure, and other configurations are the same as those of the first embodiment. The same portions or portions having the same function are denoted by the same reference numerals.

  As shown in FIG. 5, the liquid ejecting head 1 includes an actuator substrate 2 and a nozzle plate 5 installed on the lower surface LS on the droplet discharge side of the actuator substrate 2. In the actuator substrate 2, a plurality of channels 3 having openings 3 aa on the lower surface LS are arranged in the reference direction K to form a channel row 4. The nozzle plate 5 has a nozzle hole 6 communicating with the channel 3. The nozzle plate 5 includes a first protrusion 7a (protrusion 7) that fits into the opening 3aa.

  The nozzle plate 5 has a laminated structure in which a first sheet 5 a having a flat surface and a second sheet 5 b having protrusions 7 formed on the surface are laminated, and the protrusions 7 of the second sheet 5 b are openings of the channel 3. To fit. Thus, even when a large number of channels 3 are arranged at a narrow pitch in the reference direction K, the nozzle holes 6 of the nozzle plate 5 can be reliably aligned with the channels 3 of the actuator substrate 2. Further, a material that can easily form the protrusions 7 can be selected as the second sheet 5b. Other configurations are the same as those of the first embodiment or the second embodiment. Further, the nozzle plate 5 of the third embodiment may have a laminated structure of the first sheet 5a and the second sheet 5b as in the present embodiment.

(Fifth embodiment)
FIG. 6 is a schematic perspective view of a liquid ejecting apparatus 30 according to the fifth embodiment of the present invention. The liquid ejecting apparatus 30 includes a moving mechanism 40 that reciprocates the liquid ejecting heads 1 and 1 ′, and a flow path unit that supplies the liquid to the liquid ejecting heads 1 and 1 ′ and discharges the liquid from the liquid ejecting heads 1 and 1 ′. 35, 35 ′, liquid pumps 33, 33 ′ and liquid tanks 34, 34 ′ communicating with the flow path portions 35, 35 ′. The liquid ejecting heads 1 and 1 ′ use any one of the first to fourth embodiments already described.

  The liquid ejecting apparatus 30 includes a pair of conveying units 41 and 42 that convey a recording medium 44 such as paper in the main scanning direction, liquid ejecting heads 1 and 1 ′ that eject liquid onto the recording medium 44, and a liquid ejecting head. 1, 1 ′ carriage unit 43, liquid tanks 34, 34 ′ and liquid pumps 33, 33 ′ that supply the liquid stored in the liquid tanks 34, 34 ′ to the flow path portions 35, 35 ′, the liquid jet head 1, And a moving mechanism 40 that scans 1 ′ in the sub-scanning direction orthogonal to the main scanning direction. A control unit (not shown) controls and drives the liquid ejecting heads 1, 1 ′, the moving mechanism 40, and the conveying units 41 and 42.

  The pair of conveying means 41 and 42 includes a grid roller and a pinch roller that extend in the sub-scanning direction and rotate while contacting the roller surface. A grid roller and a pinch roller are moved around the axis by a motor (not shown), and the recording medium 44 sandwiched between the rollers is conveyed in the main scanning direction. The moving mechanism 40 couples a pair of guide rails 36 and 37 extending in the sub-scanning direction, a carriage unit 43 slidable along the pair of guide rails 36 and 37, and the carriage unit 43 to move in the sub-scanning direction. An endless belt 38 is provided, and a motor 39 that rotates the endless belt 38 via a pulley (not shown) is provided.

  The carriage unit 43 mounts a plurality of liquid jet heads 1, 1 ′, and ejects, for example, four types of liquid droplets of yellow, magenta, cyan, and black. The liquid tanks 34 and 34 'store liquids of corresponding colors and supply them to the liquid jet heads 1 and 1' via the liquid pumps 33 and 33 'and the flow path portions 35 and 35'. Each liquid ejecting head 1, 1 ′ ejects droplets of each color according to the drive signal. An arbitrary pattern is recorded on the recording medium 44 by controlling the timing at which liquid is ejected from the liquid ejecting heads 1, 1 ′, the rotation of the motor 39 that drives the carriage unit 43, and the conveyance speed of the recording medium 44. I can.

  In this embodiment, the moving mechanism 40 moves the carriage unit 43 and the recording medium 44 to perform recording, but instead, the carriage unit is fixed and the moving mechanism is the recording medium. It may be a liquid ejecting apparatus that records the image by moving it two-dimensionally. That is, the moving mechanism may be any mechanism that relatively moves the liquid ejecting head and the recording medium.

DESCRIPTION OF SYMBOLS 1 Liquid ejecting head 2 Actuator substrate, 2a Piezoelectric substrate, 2w side wall,
2b Cover plate 2ba, 2bb Liquid chamber 3 channel, 3a discharge channel, 3b non-discharge channel, 3aa, 3ba opening 4 channel row 5 nozzle plate, 5a first sheet, 5b second sheet 6 nozzle hole 7 protrusion, 7a, 7aa , 7ab 1st protrusion, 7b 2nd protrusion 8a common electrode, 8b individual electrode 9a common terminal, 9b individual terminal US upper surface, LS lower surface, NS surface w1, w2, w3, w4 width of opening, h height of protrusion , Wt side wall width t1, first protrusion width, r nozzle hole diameter, t nozzle plate thickness

Claims (11)

An actuator substrate in which a plurality of channels having openings on the droplet discharge side surface are arranged in a reference direction to form a channel row;
A nozzle plate having a nozzle hole communicating with the channel and installed on the surface of the actuator substrate on the droplet discharge side, and
The nozzle plate includes a protrusion that fits into the opening.   The liquid ejecting head according to claim 1, wherein the protrusion has a first protrusion that is positioned near both ends of the opening in the reference direction.   The liquid ejecting head according to claim 2, wherein the nozzle hole is positioned between two first protrusions positioned substantially in the center of the opening in the reference direction.   The liquid ejecting head according to claim 2, wherein the channel includes a discharge channel that discharges liquid and a non-discharge channel that does not discharge liquid, and the first protrusion is fitted into the opening of the discharge channel.   The liquid ejecting head according to claim 1, wherein the protrusion has a height from a surface of the nozzle plate in a range of 10 μm to 25 μm.   The liquid ejecting head according to claim 1, wherein the protrusion includes a second protrusion having a width substantially equal to a width of the opening in the reference direction.   The liquid ejecting head according to claim 6, wherein the channel includes an ejection channel that ejects liquid and a non-ejection channel that does not eject liquid, and the second protrusion is fitted into the opening of the non-ejection channel.   The liquid ejecting head according to claim 1, wherein the protrusion is positioned near both ends in an orthogonal direction orthogonal to the reference direction of the opening.   The liquid ejecting head according to claim 8, wherein the nozzle hole is positioned at a substantially center of a width of the opening in the orthogonal direction.   The liquid ejecting head according to claim 1, wherein the nozzle plate has a laminated structure in which a first sheet having a flat surface and a second sheet having the protrusions on the surface are laminated. A liquid ejecting head according to claim 1;
A moving mechanism for relatively moving the liquid ejecting head and the recording medium;
A liquid supply pipe for supplying a liquid to the liquid ejecting head;
And a liquid tank that supplies the liquid to the liquid supply pipe.

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